<!--
{
  "availability" : [
    "iOS: 13.0.0 -",
    "iPadOS: 13.0.0 -",
    "macCatalyst: -",
    "macOS: 10.15.0 -",
    "tvOS: 13.0.0 -",
    "visionOS: -",
    "watchOS: 6.0.0 -"
  ],
  "documentType" : "symbol",
  "framework" : "Accelerate",
  "identifier" : "/documentation/Accelerate/vDSP_BiquadFunctions",
  "metadataVersion" : "0.1.0",
  "role" : "Protocol",
  "symbol" : {
    "kind" : "Protocol",
    "modules" : [
      "Accelerate"
    ],
    "preciseIdentifier" : "s:10Accelerate20vDSP_BiquadFunctionsP"
  },
  "title" : "vDSP_BiquadFunctions"
}
-->

# vDSP_BiquadFunctions

A protocol that defines functions for biquadratic filtering.

```
protocol vDSP_BiquadFunctions
```

## Topics

### Associated Types

[`associatedtype Scalar`](/documentation/Accelerate/vDSP_BiquadFunctions/Scalar)

### Type Methods

[`static func applyMulti(setup: vDSP_biquadm_SetupD, pInputs: UnsafeMutablePointer<UnsafePointer<Self.Scalar>>, pOutputs: UnsafeMutablePointer<UnsafeMutablePointer<Self.Scalar>>, count: vDSP_Length)`](/documentation/Accelerate/vDSP_BiquadFunctions/applyMulti(setup:pInputs:pOutputs:count:))

[`static func applySingle<U, V>(source: U, destination: inout V, delays: UnsafeMutablePointer<Self.Scalar>, setup: vDSP_biquad_Setup, sectionCount: vDSP_Length, count: vDSP_Length)`](/documentation/Accelerate/vDSP_BiquadFunctions/applySingle(source:destination:delays:setup:sectionCount:count:))

[`static func destroySetup(channelCount: UInt, biquadSetup: OpaquePointer)`](/documentation/Accelerate/vDSP_BiquadFunctions/destroySetup(channelCount:biquadSetup:))

[`static func makeBiquadSetup(channelCount: vDSP_Length, coefficients: [Double], sectionCount: vDSP_Length) -> OpaquePointer?`](/documentation/Accelerate/vDSP_BiquadFunctions/makeBiquadSetup(channelCount:coefficients:sectionCount:))

## Relationships

### Conforming Types

[`VectorizableDouble`](/documentation/Accelerate/vDSP/VectorizableDouble)

[`VectorizableFloat`](/documentation/Accelerate/vDSP/VectorizableFloat)

---

Copyright &copy; 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)